class Solution {
    public int trap(int[] height) {
        int result = 0;
        int maxValue = -1;
        int maxAddr = 0;
        for(int i = 0;i<height.length;i++){
            if(height[i]>=maxValue){
                maxValue = height[i];maxAddr=i;
            }
        }
        //左半部分处理     
        for(int left = 0;left<maxAddr;left++){
            for(int i =left+1;i<=maxAddr;i++){
                if(height[i]<height[left])
                    result=result+(height[left]-height[i]);
                else
                    left = i;
            }
        }
        //右半部分处理
        for(int right =height.length-1;right>maxAddr;right--){
            for(int i =right-1;i>=maxAddr;i--){
                if(height[i]<height[right])
                    result=result+(height[right]-height[i]);
                else
                    right = i;
            }
        }
        return result;
    }
}